Effects of Photodynamic Therapy Using Yellow LED-light with Concomitant Hypocrellin B on Apoptotic Signaling in Keloid Fibroblasts

Keloid is a common and refractory disease characterized by abnormal fibroblast proliferation and excessive deposition of extracellular matrix components. Hypocrellin B (HB) is a natural perylene quinone photosensitizer. In this experiment, we studied the effects of photodynamic therapy (PDT) using yellow light from light-emitting diode (LED) combined with HB on keloid fibroblasts (KFB) in vitro. Our results showed that HB-LED PDT treatment induced significant KFB apoptosis and decreased KFB cell viability. HB-LED PDT treatment lead to significant BAX upregulation and BCL-2 downregulation in KFB cells, which led to elevation of intracellular free Ca(2+) and activation of caspase-3. Our data provides preliminary evidence for the potential of HB-LED PDT as a therapeutic strategy for keloid.